Hi Andrew, > On 28 Mar 2018, at 18:50, Andrew Voelkel <[email protected]> wrote: > > Hi, > > I was referred to the MachineKit group after discussing plans to switch my > router machine control from Mach3 on Windoze. He told me that people are > using the PRU on the BBB to do the stepper motor control for LinuxCNC. That > sounded attractive. > > (I have a Gecko motor driver. My system is 4 motors, but only because the x > motor is mirrored.) > > So I did a forum search here and it didn't really clear things up that much. > It was pretty down in the weeds. > > What I'm trying to figure out is whether using MachineKit LinuxCNC and the > BBB with the PRU is standard fare or not. I have basically two choices as far > as I can tell: > Use MachineKit and a BBB I have lying around, and the PRU as stepper control. > Ride off into the sunset. > Use a Mesa 7i92 for stepper motor control and standard LinuxCNC instead of > MachineKit, making sure that I have a realtime kernel installed one way or > the other. I'd probably still use the BBB as my CPU. Yes, BBB with Machinekit is standard fare. There are images you can put on an SD. Charles has made the pru_generic driver, and that basically means that step generation is done on the PRU.
If you use the BBB, you’d have to make sure you get proper isolation from the BBB pins to whatever you use down the line. It’s easy to fry a BBB. So only a PRU does not do the job. It’s the electronics coming after. Am I correct that you want to run the 7i92 from the BBB? Although I personally have no experience with this setup. You have to take into account that the BBB is not great when it comes to graphics, Axis is known to have problems when you have a lot of small segments. So if you want to have proper screens you could use a proper PC (which IMO are not very expensive). > Although I like the idea #1 above because it is a one board solution (and I > save $89), the most important thing is that I choose the system that is > easiest to set up and most reliable. In that case (depending on your budget) I’d go for a PC with a mesanet card, like the 5i25_7i76 Or depending on your skills, do some level shifting and take care of the BBB pins to your drivers. Which should definitely be doable. > > Does anyone have any opinions of which that might be? If both of these > configurations are regularly used, then I'll go with BBB and PRU and > MachineKit, since I can try it all out for the cost of my own time. But I > value my time so I don't want to get too experimental. > > Thanks for any help!! > > -- > website: http://www.machinekit.io <http://www.machinekit.io/> blog: > http://blog.machinekit.io <http://blog.machinekit.io/> github: > https://github.com/machinekit <https://github.com/machinekit> > --- > You received this message because you are subscribed to the Google Groups > "Machinekit" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > Visit this group at https://groups.google.com/group/machinekit > <https://groups.google.com/group/machinekit>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
